I think all of the things in this game, are clearly not beyond the system, so won't be beyond the PS4, and I think it'd be epic to have something, virtually identical to what we see in that youtube video (maybe leave out the obstacles, weapons, boost pads
).
The current one is a waste of time, you are given variables, which make no sense, alter one by +/-1 and the track changes in completely different ways.
Having said that, I would like the possibility to randomly generate tracks though, then tweak them, but I see no reason for this not to be a feature in GT6, don't see how anyone could be opposed to the idea, other than the time it'd take to make one with realistic scenes..
but if they use such low grade scenary in GT6 as they have in GT5 (looks like N64 graphics imo, flat people, ect, Crusin USA comes to mind), then the realism element isn't much of an issue either.